"Several trains between Agartala, Lumding, Manipur, Mizoram and southern Assam and the rest of India did not run due to the railway line blockade," a Northeast Frontier Railway spokesman told reporters in Silchar.
Trains were stopped in Tripura, Mizoram, Manipur and southern Assam Friday after a railway driver was kidnapped along with his co-driver by unidentified militants at Ramnathpur in Assam's Hailakandi district late Thursday.
Driver Tarun Kumar Bhattacharjee, 50, and co-driver Sudhir Kumar Sarmah, 47, were abducted when their train from Lala Bazar station of southern Assam was approaching Bairabi station in northern Mizoram, police Chief Hemanta Kumar Bhattacharjee told reporters.
The militants released Sarmah Friday night.
Railway and police officials were negotiating with the protesters, he said.
Many passengers were stranded in Agartala, Jiribam (Manipur), Bhairabi (Mizoram) and southern Assam's Badarpur, Silchar and Lumding stations.